Developmental neurotoxicity of polybrominated biphenyls

Female F0 generation Sprague-Dawley rats received daily oral doses of 0, 0.2, or 2 mg/kg polybrominated biphenyls (PBB) as fireMaster BP-6 from Day 6 of gestation through Day 24 postpartum. Maternal parameters were assessed, and F1 generation offspring were evaluated for growth and survival, as well as physical and behavioral development. No adverse maternal effects were observed nor were there PBB-related effects on survival of the F1 generation or acquisition of developmental landmarks. Crown-rump length of 0.2 and 2 mg/kg male offspring was significantly less than that of controls and 2 mg/kg male and female offspring gained significantly less weight than did controls for the entire 60-day postnatal observation period. An overall evaluation of behavior by multivariate analysis of variance revealed significant PBB-related effects for acquisition of forward locomotion, cliff avoidance, cage emergence, and open-field activity of male and female offspring from dams administered 2 mg/kg. Delays in acquisition of forward locomotion and suppressed open-field activity were the most prominent effects. These indications of growth retardation and neurobehavioral toxicity occurred at concentrations of PBB in offspring body fat in the range of those which have been reported for highly exposed human subjects with neurological sequelae.